I am making sauerkraut, and don't have a handy kitchen scale. What is the approximate volume of 1 lb of cabbage? Also, any advice on saurkraut making would be appreciated. This is my second batch. The first one turned out very good, but I had to throw away that last of what was in the crock as it had mold on top. I am using a Harsch Crock.
3 pounds of cabbage should net you approximately (source) 1 pint of canned sauerkraut. Otherwise, 1 lb. = 2 cups cooked; 1 lb. = 4 cups shredded. I would recommend you just weigh the cabbage when you buy it so you can have an idea of how much it will yield.
A medium-sized cabbage weighs around 2 to 2.5 pounds. (Assuming we all mean the same thing by "medium"...) I think you'll probably be better off guessing based on fraction of your whole cabbage than volume, since once you shred the cabbage, the volume's going to vary wildly depending on how fine you shred it and how fluffed up it is when you measure it. My best guess for volume would be 10-12 cups.
Of course, you can always go to the fallback and find something else in your kitchen that weighs a pound (I tend to have pasta) and try and lop off a hunk of your cabbage that weighs the same.
Edit: I did find something on about.com suggesting that a medium cabbage is two pounds. Unfortunately it claims that a two-pound head of cabbage makes 10 cups shredded, but that a medium head makes four cups. I think the ten cups is way, way closer to correct, based on experience. If you do want a volume, that would probably be a good estimate.
I'd say a scale is the only reasonable option here - In desperation I suppose you could fill a container to the brim, float the cabbage, and measure the water that overflowed (you'd be building a crude scale, really), but a scale is far more convenient, and allows getting the salt content right (2% or 2.5% weight of salt are typical aiming points, relative to the weight of the cabbage or cabbage and other stuff.)
In the course of an hour making sauerkraut the volume of the cabbage is all over the map from the original head, to the fluffy shreds (huge volume), to the salted and wilted shreds (most compact form, when compacted.) The weight is invariant unless you throw some (a bad spot) away.
If your available scale is too small for the job, measure within its capacity, multiple times.